A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

NSW police minister quits over ICAC claims

Toppled NSW Police Minister Mike Gallacher says he does not know the details of the corruption allegations made against him.

Premier Mike Baird earlier accepted Mr Gallacher's resignation as minister after the Independent Commission Against Corruption (ICAC) heard claims Mr Gallacher played a central role in a "corrupt scheme" used to funnel illegal donations to the NSW Liberal Party.

"I have spent my entire professional life fighting corruption and crime," the former police officer said on Friday.

"I am disappointed that this allegation has been made and the manner in which it came to be made but it will be dealt with through the processes of ICAC."

Mr Gallacher, who will soon be called before the corruption watchdog to give evidence, says he only heard about the allegations for the first time on Friday morning.

Asked if he denied the allegation, he replied: "I don't even know what the allegation is.

"All I've heard this morning is that I've had a corrupt, long-standing relationship.